In general, an endoscope is to be used for inspection or medical treatment by being inserted into the body of a patient, and thus the inner walls of conduits or external surfaces of the endoscope and peripheral devices attached to the endoscope are polluted, and these devices are to be cleaned and sterilized in an endoscope cleaning apparatus after use. As such a cleaning and sterilizing method, sterilization with e.g. glutaraldehyde or peracetic acid which are harmful for human body, has been commonly used.
Recently, acidic electrolytic water obtained by electrolyzing saline solution has been gaining attention, which has a property that it has a high sterilizing power though it hardly adversely affects a human body, and a method of sterilization with such electrolytic acidic water after cleaning with water, is being introduced for use. Further, in order to compensate for a disadvantage of acidic electrolytic water that the sterilizing power is decreased when dirt or organic matter remains after the cleaning before sterilization, a method of cleaning with electrolytic alkaline water before sterilization with acidic electrolytic water, has been proposed.
Endoscopes include soft endoscopes and hard endoscopes depending on the purpose of use. However, the requirement that such needs to be cleaned and sterilized with electrolytic solution of saline solution, is common for both types of endoscopes. Further, in order to further improve the cleaning effect, a method of cleaning with e.g. city tap water before cleaning with alkaline water, or a method of cleaning with a supersonic vibration propagated in a cleaning liquid by attaching a supersonic generator to a cleaning bath, has been proposed.
Heretofore, such a method of cleaning and sterilization with electrolytic solution of saline solution, has been described, for example, in JP-A-2002-45334 (page 2 column 2 to page 3 column 3 and FIG. 1). According to this method, alkaline water and acidic water obtained by electrolyzing saline solution, are once stored in a storage bath for alkaline water and a storage bath for acidic water respectively, and these alkaline water and acidic water are supplied sequentially to a cleaning apparatus to be used for cleaning. Namely, at first, dirt as a protein adhered to the inside and outside of an endoscope is dissolved or exfoliated with the alkaline water, and then, the endoscope whose dirt is removed from to the surface, is cleaned with acidic water for sterilization. Then, in order to make the sterilization with acidic water more effective, cleaning with city tap water is conducted after the cleaning with alkaline water to wash off free dirt or alkaline water, and in order to prevent oxidation-induced deterioration or corrosion of an object to be cleaned, the object is cleaned with city tap water after the sterilization with acidic water, to remove the acidic water.
Further, as an example of ultrasonic cleaning of an endoscope, JP-A-2000-300515 (page 7 column 12 to page 8 column 13, FIG. 11 and FIG. 12) may be mentioned. The method mentioned is that an ultrasonic vibrator is attached to a tray for cleaning an endoscope, and the ultrasonic vibrator is actuated when cleaning water is supplied in the tray to conduct ultrasonic cleaning of an endoscope.
In cases of conventional cleaning and sterilizing apparatuses, as described above, an electrolysis apparatus for electrolyzing saline solution to obtain alkaline water and acidic water required for cleaning and sterilizing an endoscope, is provided separately from a cleaning and sterilizing apparatus for an endoscope. Accordingly, the alkaline water and the acidic water obtained by electrolysis of saline solution are once stored in the respective storage baths, and they are sequentially supplied to the cleaning and sterilizing apparatus. Therefore, the following problems have been caused due to the fact that the electrolysis apparatus and the cleaning and sterilizing apparatus are separately provided.
Namely, a conventional electrolysis apparatus has to be provided with not only an electrolysis bath but also storage baths respectively storing alkaline water and acidic water obtained by electrolysis. Further, in order to connect these storage baths and a cleaning bath to be used, water-feeding pipes for connecting these baths are necessary. Accordingly, entire cleaning and sterilizing apparatus including the electrolysis apparatus becomes large sized or complicated to cause an increase of production cost, and such an apparatus requires a large space for installation.
Further, due to such a large size, most of conventional cleaning and sterilizing apparatuses are required to be installed at a predetermined place for use, and a limitation exists that it is necessary to bring an endoscope to the place where the cleaning and sterilizing apparatus is installed, in order to clean and sterilize the endoscope. Therefore, such an apparatus does not have such a convenience that it is movable to the site where an endoscope is used or in the vicinity of the site, so that an endoscope can be cleaned and sterilized immediately after use, to be ready for reuse.
Further, even among conventional methods, there has been a method of cleaning an endoscope with alkaline water obtained by electrolyzing saline solution, and sterilizing the endoscope with acidic water. However, there has been a problem that cleaning with alkaline water only by immersion or a swinging movement can not achieve sufficient cleaning and takes a long time, and accordingly, satisfactory sterilizing effect can not be obtained in a subsequent cleaning step with acidic water. Namely, the sterilizing effect with acidic water is obtainable by strong oxidation power of OH radicals and chlorine radicals produced by a reaction among hypochlorous acid, chlorine gas, hydrogen peroxide and high-concentration oxygen which are dissolved in the acidic water. However, if a large amount of organic matter is present with a product to be subjected to a sterilization treatment, these radicals produced tend to be consumed to oxidize the organic matter, and radicals to be used for oxidation and sterilization of bacteria, virus or the like are reduced, whereby acidic water of unnecessarily high density is required.
Further, if, e.g., protein is present, some types of such protein become solidified under certain oxidation conditions, and the oxidation effect may become less effective to, e.g., bacteria contained in such a solidified cluster. Further, a chemical solution having unnecessarily high concentration of chlorine not only accelerates corrosion of e.g. a device to be cleaned and sterilized or a cleaning and sterilizing apparatus, but also deteriorates safety of utilization environment, and its waste water may cause environmental pollution.
The present invention has been made considering the above-mentioned problems, and it is an object of the present invention to remove the storage bath for alkaline water obtained by electrolyzing saline solution, so that e.g. an endoscope can be directly cleaned and sterilized in an electrolysis apparatus with alkaline water produced in the apparatus, to down-size a cleaning and sterilizing apparatus, and thereby to provide a method and an apparatus for cleaning and sterilizing an endoscopic camera instrument etc., which is easily moved or carried.